Back and Forth
by Madam Callisto
Summary: "Sebastian began working for Jim Moriarty three years after being dishonorably discharged from the army, and the full knowledge that the man was a complete and utter psychopath did very little to deter his enjoyment of Jim's company."
1. Chapter 1

Sebastian began working for Jim Moriarty three years after being dishonorably discharged from the army, and the full knowledge that the man was a complete and utter psychopath did very little to deter his enjoyment of Jim's company. This was odd, considering as a rule, Sebastian hated everyone. He did however find something weirdly comforting about his boss's erratic and chaotic behavior. The vibe he got from Jim reminded him of his time in Afghanistan. The terror and the feeling of having no idea what was coming next; it felt like home.

That did not however in Sebastian mind, give him the right to vanish for several weeks without any warning.

Several weeks earlier, Sebastian had (at Jim's command) moved in to a flat of such close proximity to the infamous 221b Baker Street that he didn't think it'd be long before bumped into Sherlock became impossible to avoid. He had managed to however, by not once leaving the flat since initially moving in. The previous occupants of 311A Baker Street, an elderly couple in their early 60's, had very suddenly decided to move away one morning after finding the bodies of their pet dogs mutilated on their doorstep. Similar things had been happening up and down Baker Street, leaving a string of vacant houses up and down the neighborhood. Sebastian had no idea exactly _why _he'd been asked to clear out these houses, but he honestly didn't care. If Jim asked him to do it, then it was done, no questions asked. That was how it worked between them.

But two days after he'd settled himself into 311A, he stopped receiving any kind of new orders from Jim. Ordinarily, he could expect half a dozen texts a day asking what Sherlock had been up. _How often had he left the house? Was the doctor with him? How long was he gone? How did he look?_ And various other ramblings of that sort, but for the past three weeks, nothing. As much as he wished he wasn't, Sebastian was beginning to worry.

He settled himself down as he usually did most evenings that Sherlock was home, in a chair besides the row of computer screens that had been set up to maximize optimum viewing of Sherlock Holmes and John Watson's activities. Sebastian had personally set up each camera in their flat, carefully making sure their wasn't the tiniest item left out of place, making sure the slanted books were left tilted at the exact proper angle as when he had entered. His attention to detail was exactly why Moriarty trusted only him with this job.

Sebastian took a sip of coffee (he always drank coffee, couldn't afford to drink anything as relaxing as tea) as he patiently watched a black and white Sherlock and John from the camera's. They sat idly in their chairs, arguing about some small unimportant thing, messes or laptop stealing; some other piece of meaningless dribble. God, they argued like an old married couple sometimes, he thought as he sat sipping his coffee in the darkened room.

Sebastian poured a slightly substantial amount of brandy from his flask into the coffee and took another large sip. If he was going to watch this shit all night again he was gonna need a stronger drink.

The door to the flat swung open with a bang. Without a second's hesitation Sebastian turned, pulling his gun from his holster and aiming it, his instincts instantly taking over. He lowered it again as he recognized the figure.

"What the hell, Jim, it's called knocking." Sebastian said gruffly as he lowered his gun. Jim swung the door closed behind him with a sigh, not acknowledging the comment, his lock breaking tools still gripped tightly in his hands.

"You do have a key after all." He added sitting back down. Jim sat himself down on one of the many cardboard boxes that littered the room with a louder exaggerated sigh, and placed his feet up unto another. Sebastian considered warning Jim that one of boxes he was leaning against housed his assortment of guns, and that the other contained explosives, but decided against it. Jim probably already knew.

"How's our boy doing?" Jim said, biting down on his thumb.

"They just got back from a trip to Dartmoor. They were helping out a man who was convinced his father had been killed by some kind of hound. Nothing too exciting."

"A _hound? _How wonderfully archaic." Jim said, a giggle slipping from his lips, followed by a wincing sound. Sebastian turned sharply back towards him.

"What was that?" Sebastian switched on the lights.

Jim lay, sprawled comfortably across the pile of boxes, his hands tucked underneath his head. His face was decorated with a series of dark purple bruises covering his cheeks, eyes, and chin. There was blood pouring from a wound in his lip that matched the blood coming from a cut above his eye and he made no effort to stop the flow of it. Rather than his usual absurdly expensive suit, he was dressed in simple all white, or at least at one point it might have been white. Now it was soaked in spots of dark red, and caked in dirt. Jim smiled at the poorly hidden look of rage forming on his favorite henchman's face.

"Who the fuck did that to you..." He said, his voice surprising evenly despite the vein popping out of his forehead. "...and when do you want me to kill them?"

"Oh, I don't think you'll be able to get to the older Holmes anytime soon. He's quite well protected." His voice was a bored drawl, as if he was discussing drying paint.

"What, he just had you _tortured?"_

"Yes indeed. Not nearly as fun being on the other side of it I must admit."

"What do we do about the bastard then?"

"Thank him. He told me such lovely things about his little brother! I think we aught to send the man a fruit basket..."

"Couldn't I just shoot him?" Sebastian asked, scratching a hand through his stubble.

"...maybe something with mango. Mangos are always nice..."

Small droplets of blood slid down his thumb from where he was biting down on it. Sebastian dropped to one knee besides the bruised and bleeding man and pulled his hand away from his face.

"God, you look like shit."

Jim laughed, a childish, high-pitched sound. "How cruel! No one will ever marry me with now with a face like mine!" He pouted his lips innocently. Sebastian sighed and reached down into one of the cardboard boxes, pulling out a first aid kit.

"Not if I have anything to do with it." Sebastian mumbled. He wiped at the cut below Jim's lip with an alcohol soaked piece of cloth. If it stung him Jim made no outward response. He was no longer looking at Sebastian, instead staring past him at the image of Sherlock and John on the computer monitor, his face utterly blank.

Sebastian didn't bother to ask if he was hurting Jim as he had long since come to know that the man didn't really seem to have any real concept of pain, at least not in the way normal humans did. Especially when he got the look on his face that he currently had. The one that meant his brain was running through a thousand different things so quickly that Sebastian could in no way keep up. The cracked edges of his lips slowly raised themselves in a smirk as he watched Sherlock begin to pace back in forth.

"Don't you just love when he does that?" He said softly. A rhetorical question, Sebastian knew, so he said nothing, continuing to clean the blood from the man's face. "It's so relaxing. Back and forth, and back and forth, and back and forth, and back and forth..." He voice became a low whisper; his hands swinging smoothly back in forth with Sherlock's movement.

"Hold still." Sebastian said, grabbing onto Jim's hands. He examined the bloodied, nail-less fingers with a grimace. Mycroft Holmes needed very much to die.

"...back and forth, and back and forth..." Sebastian noticed the way the man always seemed to forget to blink when he was staring at Sherlock.

Sebastian began the long process of wrapping bandages over the mass of scars and bruises mapping Jim's head and hands. A few of the deeper cuts required stitches, but there was no chance of Jim risking a hospital trip so Sebastian sewed him up himself. All the while, Jim's eyes remained locked on the computer screen, the vacant look in them more akin to a starving wolf than an actual human. His ran tongue absentmindedly over his cracked lips. Sebastian hadn't seen him like this in years. Last time he'd seen that look, Sebastian had ended up burying a dozen corpses, burning down an embassy, and inciting a small civil war.

It'd been a fun weekend.

"We're going to burn it all, Sebastian." Jim all but sang, his smile light and pleasant, his eyes never leaving the screen. "And I'm going to dance on his grave."

"Yeah, sure, sounds fun." Sebastian muttered. He secured the last piece of bandage around Jim with a sigh.

"Try not to move around too much for a few days." He said, standing back up and stretching. He took a small sip of his luke-warm coffee/brandy. There was no chance of Jim taking any of his advice.

As if his very words had been a challenge, Jim sprung up from his position on the boxes with a dramatic twirl and flourish of waving arms.

"I really don't want to have to redo the stitch-"

_Thump_

Sebastian blinked, unsure for a moment why he was suddenly staring at the ceiling. It took him a moment to register that Jim had knocked him onto the floor and now sat sat perched on his chest. A wicked little laugh slipped from his lips and then grew and grew until it bounced off the walls and engulfed everything around the two of them in joyous madness. It was intoxicating. Sebastian sighed as he felt his boss's hands pulling sharply at the loop of his belt. The entire time his eyes never left the computer screens.

"Damn it, Jim." Sebastian winced at the pain radiating from the back of his head as he felt bandaged fingers run up the length of his shirt, "you didn't need to spill my coffee...".


	2. Chapter 2

No matter how many times it happened, Sebastian would never get used to waking up to the feeling of a knife cutting its way across his back. His eyes snapped open as soon as the touch of a cold blade met his bare skin. He rolled over from where he lay on the floor, pulling his handgun from his previously discarded pants and aimed in the direction on the knife. Jim lay behind him on the floor, a small glint of a smile shining in the darkness.

"One of these days I'm gonna accidentally shoot you." Sebastian said, rolling back onto his stomach, placing his gun away, and enjoying the feeling of the cold tiles on his bare body. The pants were much too far away for him to be bothered to pull them back on.

Jim pulled himself so that he was once again laying with his head on the snipers back, the knife in his hand went back tracing small patterns in Sebastian's skins, cutting deep enough to break skin, but not enough to draw blood.

"How is it that your skin has so few scars?" He asked. His blade cut small spirals across his skin.

"So few? You're literally scarring one of my scars right now."

"Hmmm, but you can't really have _enough _can you? They make your skin look so much prettier." The knife cut a bit deeper across the scar of a shallow knife wound between Sebastian's shoulder blades-one he'd actually put there himself-and the blood begin to slowly trickle down his back. Sebastian moaned slightly at the feeling of his old wound beginning to reopen but didn't pull away. The sensation had long since stopped being unpleasant to him and become in their own weird way, their version of a massage.

Without a word, the knife lifted away from Sebastian's skin and Jim got up from where he lay.

"What is it?" Jim didn't respond. The only thing lighting the room now was the light from the computers and in that light Jim was nothing but a dark silhouette. The sound of footsteps echoed through the apartment and the door swung open and then shut. He'd probably gotten an idea, found some new object to obsess over, Sebastian figured, he hoped Jim had at least bothered to take his clothes with him.

Even if there had been a bed in the flat, he probably wouldn't have bothered to get into it. Years spent sleeping out in battlefields and next to Jim Moriarty had left him able to sleep in a wide range of dangerous and uncomfortable situation, so the floor was nothing. Within a few minutes he could feel himself beginning to drift into sleep. The light of the computer screen flashed as something drifted by the camera.

Something in Sherlock's flat.

Something that was moving at three in the morning...

Sebastian turned to the computer screen with a groan.

And there he was; Jim and all his glory, standing casually in the living room of 221b Baker Street, as if he was just meant to be there. And beneath that reptilian gaze of his (made only more terrifying and empty with the addition of bandages) lay Sherlock Holmes, simple and vulnerable, passed out on the sofa.

Thank God Jim was dressed.

Sebastian pulled his pants on as he ran.

He slowed down as he reached 221b, and yanked his boots back off, placing them down outside the building. The door was already unlocked and Sebastian gently eased it open, careful not to open it far enough to let the door creak. He'd been inside the apartment enough times before to have memorized the places in the floor that squeaked, and which steps needed to be avoided to be completely silent. As quickly as possible, he leapt up the stairs, hoping that he would be in time to stop Jim from doing something rash and undoing his months and months of planning.

When he got up to Sherlock's flat he found Jim standing by where Sherlock lay, the tips of his fingers hovering over the man's pale cheek. Sebastian rushed forward to pull Jim's fingers away, but the man simply shook his head at him with a smile.

We shouldn't be here, Sebastian mouthed.

Jim took a deep breath. "_Why _not, Sebastian?" He all but shouted. Sebastian winced at his loudness but the consulting detective didn't seem to acknowledge the sound at all. He let out a sigh.

"When did you find time to drug him?"

"When you first feel asleep. A little bit of my secret ingredient slipped into the tea their landlady made. They're all done for the night" His head tilted to the side as he further examined the drugged man. "They really need better locks."

Clearly, Sebastian thought, watching the predatory way his boss watched the detective. "He looks so peaceful doesn't he? So plain, so pure, so...normal." His bandaged fingers ran across Sherlock's hairline.

"Sure he does, can we get outta here?"

"You could almost believe there wasn't such a beautiful mind hiding underneath..." The press of his fingers left small red marks in the skin.

Sebastian again pulled his hand away. "If we leave bruises he'll figure out what happened here, Jim. We should go now."

"...I could roll our pretty little friend over and have my way with him if I wanted to, Sebastian, and he wouldn't be able to do a thing to stop me..." A small laugh escaped him but the sound was hollow, and the joy didn't reach his eyes. The gaze of those dark brown orbs lowered to examine the twists and turns of the man's body that were not hidden under a blanket, searching as if every inch of pale flesh were made of gold. He wasn't joking in the slightest. Sebastian felt his finger twitch.

"I'm pretty sure that would count as leaving bruises."

"Not feeling jealous are we my dear?"

Sebastian snorted. "Why be jealous of a dead man?"

"You didn't answer the question."

"No, I'm not."

"Good. Jealous is a dull emotion away. So unbecoming!" His fingers reached down and pulled open the top button of Sherlock's rope with an easy flick. Sebastian swung his arm around Jim's neck from behind, squeezing non to gently as he pulled them both away.

Jim giggled in response. "Oh, Sebastian, I do love when you get rough with me! What was it you said about not being jealous?"

"Fine, you proved your point. I'm a little bit jealous and you, as always, as the master of reading us fair minded simpletons."

"That's all I needed to hear." He said, his voice a low hiss. Jim reached an arm back and dug his fingers into the small of his back, right over where his reopened scars were. Sebastian flinched and released him slowly, still not sure if his boss actually intended to leave or not.

With a sigh Jim ran his fingers through Sherlock's hair one last time, relishing the way the curls parted obediently at the touch of his fingers, and then without another word, he left with a skip in his step. Sebastian was as always, right behind him.

He was never _too_ jealous when his boss found himself a new toy to play with because honestly, they never lasted that long. In a matter of months this new favorite plaything would be dead and forgotten, and Jim will have moved onto new better things. But Sebastian wouldn't be thrown aside. Sebastian was always needed by the consulting criminal, so even if his boss never directed that cold reptilian gaze in his direction, he knew he would always be around.

And as Jim threw him against the doorframe and once again began pulling at his closes, this knowledge would make him happy in ways he never could quite explain.

The next morning, Sherlock Holmes awoke on his couch with a headache that would embarrass any past headaches he'd ever gotten with its magnitude. He remembered falling asleep the previous night on the couch after being unusually exhausted, but wasn't used to sleeping so completely through the night. In the end he decided to get himself some ibuprofen and attribute his headache to the gas they'd been exposed to during the HOUND case.

As he got up he placed a hand against the side of his aching head and instantly noticed something was horribly wrong. He got up to inspect his hair further in the mirror.

There were two less curls in hair this morning than there had been last night. They'd been detangled, but not in a way concurrent with his movement during sleep. Sherlock had fallen asleep on his right side and wasn't the type to toss and turn much. The curls that had been detangled had been on the left side of his head. Sherlock's heart sped up. The top button of his shirt was also undone, something that could in no way be attributed to his sleeping pattern. The only logical conclusion was that someone had, during the night while he slept-

"Morning, Sherlock." Sherlock jumped at the sudden entrance of John who yawned and stretched as he entered. "Sleep well?"

He opened his mouth slightly but words failed to properly form in his mind. John frowned at the sight of the man who almost always has something snide or clever to say in a state of loss for words.

"Are you alright?"

A splash of color crawled up Sherlock's face and he nodded as he pulled his hands away from his hair quickly. "Yes. Perfectly fine. Excuse me." He turned to and sped off into the bathroom, giving John an excessive and unnecessary amount of space in the process.


End file.
